A standard slide fastener has a pair of longitudinally extending and parallel textile tapes having thickened longitudinal edges that are transversely juxtaposed and that are provided with respective longitudinally extending rows of transversely projecting and interleavable coupling teeth. A slider having slots fittable over the edges can be moved along the edges over the teeth in one longitudinal direction for interleaving the teeth and coupling the tapes together transversely and in the opposite direction for disengaging the teeth from each other and decoupling the tapes from each other. The lower end of the fastener is provided with reinforcement tabs on which is mounted a separator comprised of a lug on each of the tape edges and a pocket or socket on the one tape so that the lugs can be united prior to closing the fastener with the slider.
Slide fasteners are invariably made in high-volume mass-production operations so that they can be produced at low unit costs. In the standard prior-art fastener the connection between the support tapes and the reinforcement tabs and between these tabs and the end lugs of the separator is typically a simple welded joint. Such a joint is often inadequately strong, so that it is at this location that the fastener will fail. The use of different incompatible resins is one of the reasons for such failure as, for instance, welding the reinforcement tabs to the textile tapes is problematic.